MPPT Controller Fixed Duty Cycle Mode for PV Testing

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Solution Overview

Problem

Conventional Maximum Power Point Tracking (MPPT) controllers interfere with photovoltaic device production line testing, overheat during reverse current operations, and are not suited for parallel coupled string applications, limiting their use in photovoltaic device production and testing.

Innovation Solution

Development of MPPT controllers with a fixed duty cycle operating mode, in addition to an MPPT operating mode, allowing them to be used during production line tests and with reverse current, supporting flash and electroluminescence testing, and enabling efficient operation in parallel coupled string applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional MPPT controllers are used during photovoltaic device production line testing, then power extraction is maximized during normal operation, but testing is interfered with and device quality assessment is compromised

Engineering Contradiction:

Improvepower extractionVSAvoidtesting accuracy

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The controller dynamically switches between MPPT operating mode and fixed duty cycle operating mode based on whether the photovoltaic device is undergoing production line testing or normal operation. This dynamic adaptation allows the controller to maximize power extraction during normal operation while enabling accurate testing during production line assessment

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller changes its operating parameters by switching between two distinct modes: MPPT mode for maximum power extraction and fixed duty cycle mode for testing compatibility. This parameter change allows the system to adapt to different operational requirements without hardware modification

Inventive Principle:

Principle #35Parameter changes

2Power

If conventional MPPT controllers operate during reverse current operations, then power tracking is maintained, but the controllers overheat and are damaged

Engineering Contradiction:

Improvepower trackingVSAvoidcontroller temperature

Core Design Contradiction:

PowerVSTemperature

Solution Approach 1:

The controller detects reverse current conditions and converts the potentially harmful situation into a beneficial one by switching to fixed duty cycle operating mode. This mode allows reverse current to flow through the photovoltaic device in a controlled manner that prevents overheating while still enabling useful operations such as electroluminescence testing and parallel coupled string applications

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Quantity of substance

If conventional MPPT controllers are used in parallel coupled string applications, then system capacity is increased, but the controllers are not suited for such applications and performance is degraded

Engineering Contradiction:

Improvesystem capacityVSAvoidcontroller suitability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The controller achieves multi-functionality by being suitable for both individual photovoltaic device operation and parallel coupled string applications. The fixed duty cycle operating mode enables the controller to handle reverse current scenarios that occur in parallel configurations, while the MPPT mode maintains efficiency for individual device operation, making the controller universally applicable

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9966899B2Systems and methods for controlling maximum power point tracking controllers

Publication Date: 2018.05.08 VOLTERRA SEMICONDUCTOR CORPORATION

AI summary

A method for testing a photovoltaic device electrically coupled to an input port of a maximum power point tracking (MPPT) controller, where the MPPT controller includes a switching circuit adapted to transfer power between the input port and an output port of the MPPT controller, includes the steps of: (a) driving a test current into the output port of the MPPT controller; (b) detecting presence of the test current; and (c) in response to detecting presence of the test current, causing the switching circuit to provide a path for the test current from the output port to the photovoltaic device.